Web-based diagram editor for the ATLAS Technical Coordination Expert System - Abstract and Implementation Overview

Oct 26, 2026

Upload by Mia

This document presents a new web-based diagram editor for the ATLAS Technical Coordination Expert System. The editor replaces the MXgraph-based graph rendering that has reached end of development and is no longer supported. It simulates the experiment infrastructure to support intervention preparation and handling of unforeseen situations. The proposed framework supports end-to-end diagram creation, rendering, XML storage, server communication, and diagram property updates, enabling independence from external diagram tools.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages6

Reading Time15 min

AccessFree to download

1 Introduction

2 Research motivation and description

3 A new diagram editor framework

Web-based diagram editor for use in the ATLAS Technical Coordination Expert System Sebastien Strban, CERN Summer Student (EP-ADO-SO) August 2022 Abstract This document describes a new web-based diagram editor for the ATLAS Technical Coordination Expert System, a tool that simulates the infrastructure of the experiment to prepare interventions and understand unforeseen situations. The proposed web-based diagram editor is an alternative to the graph rendering of the tool that aims to replace the libraries that have reached the end of development cycle and are not supported anymore. This document also describes the seamless integration of the newly developed framework into the tool that can be used to create new diagrams. 1 Introduction The ATLAS Technical Coordination Expert System [1] has a web-based user interface based on PHP and JavaScript, a server relying on a large Python codebase, and an object-oriented database to connect elements using different relationships based on the TDAQ Configuration Database specific to the ATLAS experiment [2] known as OKS [3] . Each object in the database has a UID (unique identifier) and is linked to other objects through dependency relationships, an object can be required by another object or can provide a functionality to another object. The data in the database is inserted from a wide range of documentation sources through a series of Python utilities. The current implementation of the Expert System uses MXgraph library [4] to render vector graphics inside the expert system. The end of development of this library requires the use of a different system to render graphics. This motivated us to find an alternative solution for representing, rendering, and viewing diagrams in a robust way. This solution is seamlessly integrated into the system. Since only a small part of the MXgraph library was previously used, we decided to create our own diagram rendering library. Furthermore, we expanded the rendering part of the library with the editing part and created a diagram editor framework. This enabled us to design and also render a diagram in the same framework. The diagram editor framework is also able to store generated diagrams as an XML file, and capable of communicating with the server, retrieve data, and update the diagram properties based on it. The proposed implementation enabled us to become independent of previously used external tools to design diagrams and MXgraph library to render graphics. 2 Research motivation and description The MXgraph library is a full client-side JavaScript diagramming library that uses HTML and SVG. The diagrams are stored in a custom XML format, and rendered on the web page using SVG. The implementation of a new diagram in the MXgraph library requires two steps. First, a new XML diagram needs to be created, which is typically done with an external tool such as DrawIO [5], that is based on the same library. At this point the objects in the diagram need to include the UID tag in order to be represented properly by the system. Second, after the XML has been stored in the web server, the system would use the MXgraph library to parse and render the XML diagram as an SVG and display HTML tags on top that allow for the interactivity of the user. Since the MXgraph library reached the end of development it poses serious limitations to the further development and maintenance of the Expert System. Furthermore, this introduced a lot of incompatibilities with the external tools used for drawing diagrams, which are still currently being actively developed. There are some alternatives to MXgraph, available as forked repositories [6, 7, 8] . Some libraries use JavaScript [7, 8] and some TypeScript [6], and some have been discontinued [7] . There are also some alternative solutions to this library. One could use a toolbox for displaying and modifying diagrams on the web [9] . Another solution would be to use proprietary JavaScript library for impleme

FAQs

What problem does the new diagram editor address in the ATLAS Technical Coordination Expert System?

It addresses limitations of the MXgraph library, which has reached end of development, by replacing the previous diagram rendering approach with a more maintainable web-based solution.

How does the editor workflow differ from the previous MXgraph approach?

The previous workflow required creating an XML diagram with an external tool and then parsing and rendering it with MXgraph; the new framework aims to enable creating, rendering, storing, and updating diagrams within the system itself.

What capabilities does the proposed diagram editor framework include?

It supports direct manipulation and automatic updates of diagram content, stores generated diagrams as XML, communicates with the server to retrieve data, and updates diagram properties based on retrieved information.

Oct 26, 2026

Upload by Mia